Spinal fusion surgery for degenerative disc disease involves removing the damaged disc and replacing it with bone grafted from another site on the patient's body, bone from a donor, or artificial or synthetic bone graft material that stimulates bone growth to fuse, or join, the two vertebrae together to stabilize the spine. In all spinal interbody fusion surgeries, disc material is removed. A spacer, referred to as a “cage” is then inserted into the disc space.
Bone cages require the use of specialized instruments for insertion and adjustment. Many bone cages require the use of multiple instruments in order to properly insert and adjust the bone cage. This is not desirable because the removal and insertion of additional instruments during spinal fusion surgery can cause damage to the surrounding nerves as well as the spinal cord.
There are many types of bone cages known in the art. One example of an expandable bone cage is disclosed by U.S. patent application Ser. No. 12/848,797, filed on Aug. 2, 2010, and herein incorporated by reference. U.S. patent application Ser. No. 12/848,797 discloses a bone cage with components that allow for controlled expansion.
Other bone cages known in the art are filled with bone graft material outside of the body before the cage is inserted into the disc space. When the cage is hammered during insertion, bone graft material may leak from the bone cage and into the spinal canal where it can damage the nerves.
It is desirable to have a bone cage placement device that allows bone graft material to be inserted into the bone cage after it has been inserted into the disc space.
It is desirable to have a bone cage placement device that allows a bone cage to be inserted, adjusted, and expanded, and which allows bone graft material to be inserted and an end plug positioned using a single device.